JPH0423099B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a learning control device for a feedback control system for controlling the air-fuel ratio, idle speed, etc. of an internal combustion engine.

<Prior Art> Conventional learning control devices for internal combustion engines include, for example, an air-fuel ratio learning control device disclosed in Japanese Patent Application Laid-open No. 59-203828, and an air-fuel ratio learning control device disclosed in Japanese Patent Application Laid-Open No. 59-211738. There is a disclosed idle speed learning control device.

Here, a base air-fuel ratio learning control device will be described as an example in the case where the air-fuel ratio is feedback-controlled to the stoichiometric air-fuel ratio, which is a control target value, in an internal combustion engine having an electronically controlled fuel injection device.

The fuel injection valve used in an electronically controlled fuel injection system is opened by a drive pulse signal applied in synchronization with engine rotation, and during the valve opening period, fuel at a predetermined pressure is injected. . Therefore, the fuel injection amount is controlled by the pulse width of the drive pulse signal, and if this pulse width is set as Ti and the control signal corresponds to the fuel injection amount, then in order to obtain the stoichiometric air-fuel ratio, Ti is determined by the following equation. It will be done.

Ti=Tp・COEF・α+Ts However, Tp is the basic pulse width corresponding to the basic fuel injection amount and is called the basic fuel injection amount for convenience. Tp=
K・Q/N, where K is a constant, Q is the intake air flow rate, and N
is the engine speed. COEF is various correction coefficients such as water temperature correction. α is an air-fuel ratio feedback correction coefficient for air-fuel ratio feedback control (λ control) to be described later. Ts is a voltage correction amount, which is used to correct changes in the injection flow rate of the fuel injector due to changes in battery voltage.

Regarding λ control, an O ₂ sensor is installed in the exhaust system to detect the actual air-fuel ratio, and whether the air-fuel ratio is richer or leaner than the stoichiometric air-fuel ratio is controlled by the slice level. A feedback correction coefficient α is determined, and by varying this α, the stoichiometric air-fuel ratio is maintained.

Here, the value of the air-fuel ratio feedback correction coefficient α is changed by proportional-integral PI control to achieve stable control.

In other words, the output voltage of the O ₂ sensor is compared with the slice level voltage, and if it is higher or lower than the slice level, the air-fuel ratio is rich (lean) without suddenly enriching or thinning the air-fuel ratio. ), the air-fuel ratio is controlled to be leaner (richer) by first lowering (raising) it by P, and then gradually lowering (raising) it by I.

However, under conditions where λ control is not performed, α
The desired air-fuel ratio is obtained by clamping and setting various correction coefficients COEF.

By the way, the base air-fuel ratio under λ control conditions, that is, the air-fuel ratio when α=1, is the stoichiometric air-fuel ratio (λ
= 1), there is no need for feedback control; however, in reality, it is difficult to control due to variations in component parts (for example, air flow meters, fuel injection valves, pressure regulators, control units), changes over time, and fuel injection. Feedback control is performed because the base air-fuel ratio deviates from λ=1 due to factors such as non-linearity in the pulse width-flow rate characteristic of the valve and changes in operating conditions and environment.

However, if the base air-fuel ratio deviates from λ=1, it takes time to stabilize the step in the base air-fuel ratio to λ=1 through feedback control when the operating range changes significantly. For this purpose, the proportionality and integral constants (P/I) are increased, which causes overshoot and undershoot, resulting in poor controllability. In other words, if the base air-fuel ratio deviates from λ=1, the air-fuel ratio will be controlled within a range that deviates considerably from the stoichiometric air-fuel ratio.

As a result, the three-way catalyst is operated at a point where its conversion efficiency is poor, and not only does the cost increase due to the increase in the amount of precious metal in the catalyst, but the conversion efficiency further deteriorates as the catalyst deteriorates, forcing the catalyst to be replaced. .

Therefore, by setting the base air-fuel ratio to λ = 1 through learning, the deviation from λ = 1 caused by the step in the base air-fuel ratio during transient times can be eliminated, and the P/I
The applicant has developed an air-fuel ratio learning control device that improves controllability by making it possible to reduce the
It was filed as Japanese Patent Application No. 58-76221 (Japanese Unexamined Patent Publication No. 59-203828) or Japanese Patent Application No. 58-197499.

This is because if the base air-fuel ratio deviates from the stoichiometric air-fuel ratio during air-fuel ratio feedback control, the air-fuel ratio feedback correction coefficient α increases to fill the gap. Detected, the learning correction coefficient Kl based on the α is calculated and stored, and when the same operating condition is resumed, the base air-fuel ratio is made more responsive to the stoichiometric air-fuel ratio by using the memorized learning correction coefficient Kl. to correct. Here, the learning correction coefficient Kl is stored for each region of a predetermined range obtained by dividing the RAM map into a grid according to appropriate parameters of the engine operating state such as engine speed and load.

Specifically, a map of the learning correction coefficient Kl corresponding to engine operating conditions such as engine speed and load is provided in RAM, and when calculating the fuel injection amount Ti, the basic fuel injection amount Tp is calculated as shown in the following formula. is corrected by Kl.

Ti=Tp・COEF・Kl・α＋Ts Then, learn Kl by following the steps below.

In the steady state, the region of the engine operating state at that time is detected, and the deviation Δα from the reference value of α is detected as an average value. The standard value is λ=1
It is generally set to 1.0 as the value corresponding to .

The Kl that has been learned up to now corresponding to the region of the engine operating state is searched.

The value of Kl+Δα/M is determined from Kl and Δα, and the memory is updated using the result (learning value) as a new Kl _(oew) . M is a constant.

In addition, the idle speed learning control device is used when an idle control valve is provided in the auxiliary air passage that bypasses the throttle valve, and the idle speed is controlled by adjusting the opening degree of this idle control valve. When performing feedback correction on the basic opening degree of the idle control valve corresponding to the target idle speed for each temperature by comparing the target idle speed and the actual idle speed, it is adjusted according to the cooling water temperature, which is a parameter of the engine operating state. A map of learning correction amount is provided,
The deviation of the feedback correction amount from the reference value is learned and the learning correction amount is corrected, and the basic opening degree is corrected using this learning correction amount, thereby stabilizing the control.

<Problems to be Solved by the Invention> By the way, in the conventional learning control device for an internal combustion engine, the engine operating state is detected from its parameters (for example, the rotation speed N and the load (basic fuel injection amount Tp)), and these It determines in which of multiple regions the engine operating state is divided by the grid axes, and when the engine operating state is within a certain region, the deviation from the reference value of the feedback correction amount in that region is taken as the average value. , the learning correction amount is corrected and stored for each area.

However, the following problems arose in setting the area.

Increasing the area increases learning opportunities and makes learning easier, but accuracy deteriorates.

Making the region smaller improves accuracy, but makes it harder to learn.

In order to capture the deviation of the feedback correction amount, it is necessary for the feedback correction amount to increase and decrease periodically, that is, the control must be in a steady state. , it is necessary to set an area in which the user can stay in that area, and setting the area is difficult.

Even if a certain range is set, learning efficiency may not be optimal depending on the driver's habits.

Therefore, an object of the present invention is to solve such problems in setting areas.

<Means for Solving the Problems> In order to achieve the above object, the present invention automatically corrects the lattice axes that partition the regions so as to achieve optimal learning efficiency according to the engine operating state. This is what I did.

Specifically, the learning control device according to the present invention has a first
As shown in the figure, the following means (A) to (J) are provided.

(A) Basic control amount setting means for setting basic control amounts corresponding to control target values such as air-fuel ratio and idle speed; (B) A grid axis that divides the engine operating state into a plurality of regions according to the parameters; (C) A rewritable storage means that stores learning correction amounts for correcting the basic control amount for each area surrounded by these grid axes. Learning correction amount search means (D) for searching the learning correction amount Compares the control target value and the actual value and sets the feedback correction amount by a predetermined amount to correct the basic control amount so that the actual value approaches the control target value. Feedback correction amount setting means (E) that increases or decreases the basic control amount set by the basic control amount setting means, the learning correction amount searched by the learning correction amount searching means, and the feedback correction amount setting means set by the feedback correction amount setting means. Controlled amount calculation means (F) that calculates a controlled amount from the feedback correction amount Control means (G) that operates according to the control amount to control the air-fuel ratio, idle speed, etc. Steady state detection means (H) that detects a steady state by being in one arbitrary region.Direction 2 to learn the average value of the deviation from the reference value of the feedback correction amount during that time when detecting the steady state and reduce it. learning correction amount correction means (I) that corrects and rewrites the learning correction amount corresponding to the area of the engine operating state during that time; engine operating state averaging means that calculates the average value of the actual engine operating state during learning of the deviation; (J) A lattice axis correction means for correcting and rewriting the lattice axis that divides the area in a direction in which the average value of the engine operating state becomes the center of the area including the average value of the engine operating state at the same time as the learning correction amount is corrected (Operation) Basic control The amount setting means A sets the basic control amount corresponding to the control target value such as the air-fuel ratio and the idle rotation speed, for example, according to a predetermined calculation formula or by searching, and the learning correction amount retrieval means C sets the basic control amount corresponding to the control target value such as the air-fuel ratio and the idle speed. ,
The feedback correction amount setting means D searches for the learning correction amount in the corresponding region based on the actual engine operating state, compares the control target value and the actual value, and sets the feedback correction amount so that the actual value approaches the control target value. For example, it is set by increasing or decreasing a predetermined amount based on proportional-integral control. Then, the control amount calculation means E calculates the control amount by correcting the basic control amount with the learning correction amount and further correcting it with the feedback correction amount. The injection amount or auxiliary air amount is controlled to control the air-fuel ratio, idle speed, etc.

Here, in the storage means B, it is possible to rewrite both the grid axes that divide the engine operating state into a plurality of regions according to one or two parameters, and the learning correction amount for each region surrounded by these grid axes. In the above-mentioned search by the learning correction amount retrieval means C, the area between the grid axes where the actual operating condition exists is known, and the learning correction amount for the corresponding area is read.

Steady state detection means G detects that the actual engine operating state is in a steady state when it exists continuously and stably in any one region, and knows that it is a learnable state.

When it is determined that the state is ready for learning, the learning correction amount is corrected and rewritten by the learning correction amount correction means H, and the lattice that divides the area is corrected by the engine operating state averaging means I and the grid axis correction means J. Correct/rewrite the axis.

The learning correction amount modifying means H learns the average value of the deviation of the feedback correction amount from the reference value during the steady state detection, and corrects the learning correction amount corresponding to the region of the engine operating state during that time in a direction to reduce this. The data in storage means B is rewritten.

The engine operating state averaging means I calculates the average value of the actual engine operating state during learning of the deviation, and the grid axis correction means J calculates the average value of the engine operating state while correcting the learning correction amount. The data in the storage means B is rewritten by correcting the lattice axis that partitions the area in the direction of the center of the area that includes it.

In other words, we start learning with the lattice axes that were matched using the conventional method, and each time the learning is successful, we capture the range of movement of the parameter representing the engine operating state during learning, and calculate the average value of that movement. The lattice axes are automatically corrected so that they are at the center of the area.

<Embodiment> An embodiment in which the learning control device of the present invention is applied to an air-fuel ratio feedback control system of an internal combustion engine having an electronically controlled fuel injection device will be described below.

In FIG. 2, air is taken into the engine 1 through an air cleaner 2, an intake duct 3, a throttle chamber 4, and an intake manifold 5. As shown in FIG.

The intake duct 3 is provided with an air flow meter 6 as means for detecting the intake air flow rate Q, and outputs a voltage signal corresponding to the intake air flow rate Q signal. The throttle chamber 4 is provided with a primary throttle valve 7 and a secondary throttle valve 8 which are operated in conjunction with an accelerator pedal (not shown) to control the intake air flow rate Q. Further, an auxiliary air passage 9 is provided that bypasses these throttle valves 7 and 8, and an idle control valve 10 is interposed in this auxiliary air passage 9. A fuel injection valve 11 is provided in the intake manifold 5 or the intake port of the engine 1 . This fuel injection valve 11 is an electromagnetic fuel injection valve that opens when the solenoid is energized, and closes when the energization is stopped. Fuel controlled to a predetermined pressure by a pressure regulator is injected and supplied to the engine 1. Therefore, the fuel injection valve 11 is a control means for controlling the fuel injection amount by its operation and controlling the air-fuel ratio to the optimum air-fuel ratio (stoichiometric air-fuel ratio) which is a control target value.

Exhaust gas is exhausted from the engine 1 via an exhaust manifold 12, an exhaust duct 13, a three-way catalyst 14, and a muffler 15.

The exhaust manifold 12 is provided with an O ₂ sensor 16 . This O ₂ sensor 16 outputs a voltage signal according to the ratio of the oxygen concentration in the atmosphere (constant) and the oxygen concentration in the exhaust gas, and is known to cause a sudden change in electromotive force when the air-fuel mixture is combusted at the stoichiometric air-fuel ratio. It is a sensor of Therefore, the O ₂ sensor 16 is a means for detecting the air-fuel ratio (rich/lean) of the air-fuel mixture. Three-way catalyst 14
is a catalyst device that efficiently oxidizes or reduces CO, HC, and NOx in exhaust gas near the stoichiometric air-fuel ratio of the air-fuel mixture and converts them into other harmless substances.

In addition, a crank angle sensor 17 is provided. The crank angle sensor 17 is connected to the crank pulley 1
8 is provided with a signal disk plate 19,
For example, the teeth provided on the outer periphery of the plate 19
Outputs a reference signal every 120 degrees and a position signal every 1 degree. Here, the engine rotation speed N can be calculated by measuring the period of the reference signal. Therefore, the crank angle sensor 17 is a means for detecting not only the crank angle but also the engine speed N.

The air flow meter 6 and the crank angle sensor 1
7 and the O ₂ sensor 16 are both input to a control unit 30. Furthermore, the voltage of a battery 20 is applied directly to the control unit 30 via an engine key switch 21 as its operating power source and for detecting the power supply voltage. Furthermore, the control unit 30 includes, as necessary, a water temperature sensor 22 for detecting the engine cooling water temperature, a throttle sensor 23 including an idle switch for detecting the throttle opening of the primary throttle valve 7, and a vehicle speed sensor 2 for detecting the vehicle speed.
4. A signal from a neutral switch 25 or the like that detects the neutral position of the transmission is input. The control unit 30 performs arithmetic processing based on various input signals, outputs a drive pulse signal with an optimum pulse width to the fuel injection valve 11, and obtains a fuel injection amount for obtaining an optimum air-fuel ratio.

As shown in FIG. 3, the control unit 30 includes a CPU 31, a P-ROM 32, a CMOS-
It has a RAM 33 and an address decoder 34. Here, the RAM 33 is a rewritable storage means for learning control, and as an operating power source for the RAM 33, a battery 20 is used as the operating power source without using the engine key switch 21 in order to retain the memory contents even after the engine key switch 21 is turned off. Connect via a stabilized power supply.

Among the input signals to the CPU 31, each voltage signal from the air flow meter 6, O ₂ sensor 16, battery 20, water temperature sensor 22, and throttle sensor 23 is an analog signal. The signal is input via a converter 36. The A/D converter 36 is controlled by the CPU 31 via an address decoder 34 and an A/D conversion timing controller 37. The reference signal and position signal from the crank angle sensor 17 are inputted via a one-shot multi-circuit 38. The signal from the idle switch built into the throttle sensor 23 and the signal from the neutral switch 25 are inputted via the digital input interface 39, and the signal from the vehicle speed sensor 24 is inputted via the waveform shaping circuit 40. It's getting old.

An output signal from the CPU 31 (a driving pulse signal for the fuel injection valve 11) is sent to the fuel injection valve 11 via a current waveform control circuit 41.

Here, the CPU 31 performs input/output operations, arithmetic processing, etc. according to a program (stored in the ROM 32) based on the flowchart (fuel injection amount calculation routine and learning subroutine) shown in FIGS. 4 and 5. Controls fuel injection amount.

Furthermore, basic control amount (basic fuel injection amount) setting means,
Learning correction amount (coefficient) search means, feedback correction amount (coefficient) setting means, control amount (fuel injection amount) calculation means, steady state detection means, learning correction amount (coefficient)
The functions of the correcting means, the engine operating state averaging means, and the grid axis correcting means are achieved by the program.

Next, the operation will be explained with reference to the flowcharts of FIGS. 4 and 5.

In FIG. 4, in step 1 (S1 in the figure), basic fuel injection is performed based on the intake air flow rate Q obtained from the signal from the air flow meter 6 and the engine speed N obtained from the signal from the crank angle sensor 17. Calculate the quantity Tp (=K·Q/N). This part corresponds to the basic control amount setting means.

In step 2, various correction coefficients COEF are set.

In step 3, a corresponding learning correction coefficient Kl is searched from the engine speed N representing the engine operating state and the basic fuel injection amount (load) Tp. This part corresponds to the learning correction amount search means.

Here, as shown in FIG. 6, the learning correction coefficient Kl is calculated based on, for example, the lattice axes N ₁ to _{N 8} and the lattice axes, with the horizontal axis representing the engine speed N and the vertical axis representing the basic fuel injection amount Tp.
Tp ₁ to _{Tp 8} predetermine 64 regions of the engine operating state surrounded by these and
3, the learning correction coefficient Kl is stored for each area. Specifically, if we fix the number of regions and give them symbols A ₁₁ to _{A 88} for convenience, then for region A _oo , the intersection of the lower left lattice axis _No and the lattice axis Tp _o (lattice The values of N and Tp of point) are stored, as well as the learning correction coefficient Klo _oo . Note that at the time when learning has not started, the lattice axes N ₁ to _{N 8} and Tp ₁ to Tp ₈ are predetermined by matching (unequal pitches are fine), and the learning correction coefficients Kl are all initially set to 1. .

In step 4, a voltage correction amount Ts is set based on the voltage value of the battery 20.

In step 5, it is determined whether the λ control condition is met.

Here, if the condition is not λ control condition, for example, high rotation, high load region, etc., the air-fuel ratio feedback correction coefficient α is clamped to the previous value (or reference value α ₁ ), and the steps from step 5 to be described later are performed.
Proceed to step 10.

For λ control conditions, steps 6 to 8
The output voltage of the O ₂ sensor 16 is compared with the slice level voltage to determine whether the air-fuel ratio is rich or lean, and the air-fuel ratio feedback correction coefficient α is set by integral control or proportional-integral control. This part corresponds to the feedback correction amount setting means. Specifically, in the case of integral control, when the air-fuel ratio is determined to be rich as a result of the comparison in step 6, the air-fuel ratio feedback correction coefficient α is decreased by a predetermined integral I from the previous value in step 7; When it is determined that the fuel ratio is lean, in step 8 the air-fuel ratio feedback correction coefficient α is increased by a predetermined integral I with respect to the previous value. In the case of proportional-integral control, in addition to this, when reversing rich←→lean, an increase or decrease is performed by a predetermined proportional amount P, which is larger than the integral I, in the same direction as the integral I (see FIG. 7).

In the next step 9, the learning subroutine shown in FIG. 5 is executed. This will be discussed later.

Thereafter, in step 10, the fuel injection amount Ti is calculated according to the following equation. This part corresponds to the control amount calculation means.

Ti=Tp・COEF・Kl・α+Ts When the fuel injection amount Ti is calculated, a drive pulse signal with a pulse width of that Ti is output at a predetermined timing in synchronization with the engine rotation, and is output via the current waveform control circuit 41. is applied to the fuel injection valve 11, and fuel injection is performed.

Next, the learning subroutine shown in FIG. 5 will be explained.

Engine rotation speed N indicating the engine operating status in step 11
It is determined whether or not the basic fuel injection amount Tp and the basic fuel injection amount Tp are in the same range as the previous time. If it is the same area as the previous time, it is determined in step 12 whether flag F is set, and if it is not set, step 13 is performed.
Determine whether the output of the O ₂ sensor 16 has reversed or not, and repeat this flow and repeat the steps each time the output is reversed.
At 14, increase the count value representing the number of reversals by 1, and
When the flag F becomes equal to 2, the process proceeds from step 15 to step 16, where flag F is set. This flag F is set when the output of the O ₂ sensor 16 inverts twice in the same area, as it is assumed that a steady state has been reached. After flag F is set, if it is determined in step 11 that the area is the same as the previous one, the process advances to step 17 via step 12. This portion of steps 11 to 16 corresponds to steady state detection means.

In a steady state, it is determined in step 17 whether or not the output of the O ₂ sensor 16 has reversed, and when this flow is repeated and it has reversed, it is the first time since the steady state was determined in step 18, and therefore, it is determined whether the output of the O 2 sensor 16 has reversed or not. Determine whether it is the third reversal, and if it is the third, step 19
Then, the deviation Δα (=α−α ₁ ) of the current air-fuel ratio feedback correction coefficient α from the reference value α ₁ is temporarily stored as Δα ₁ . Then, in step 20, the integrated values ΣN, ΣTp and the sampling number m for determining the average values of the engine speed N and basic fuel injection amount Tp are cleared, and then in step 21, the current engine speed N is added to ΣN. Then, the current basic fuel injection amount Tp is added to ΣTp, and m is increased by 1. After the third reversal, 4
Step 17 until the second reversal is detected.
The program then proceeds to step 21, where integration is continued to obtain the average values of the engine speed N and the basic fuel injection amount Tp. Step when fourth reversal is detected
Proceed to steps 22 to 29 and perform learning based on the data from the third reversal to the fourth reversal (see Figure 7).
Similarly, when a fifth or more reversal is detected, the program proceeds to steps 22 to 29 and performs learning based on data from the previous reversal to the current reversal.

At the time of the fourth or more reversal, in step 22, the deviation Δα (=α−α ₁ ) from the reference value α ₁ of the current air-fuel ratio feedback correction coefficient α is temporarily stored as Δα ₂ . Δα ₁ and Δα ₂ stored at this time are the maximum and minimum values of Δα from the previous (e.g., third) reversal to the current (e.g., fourth) reversal, as shown in FIG. The average value of the deviation Δα during this time can be calculated based on .

Therefore, in step 23, the deviation Δα is calculated based on the following formula:
Calculate the average value.

=(Δα ₁ +Δα ₂ )/2 Next, in step 24, the stored learning correction coefficient Kl corresponding to the current area is retrieved. However, in reality, the one searched in step 3 may be used.

Next, in step 25, a new learning correction coefficient Kl is calculated from the current learning correction coefficient Kl and the average value of the deviation Δα (= α - α ₁ ) of the air-fuel ratio feedback correction coefficient α from the reference value α ₁ according to the following formula. _(oew) , correct and rewrite the learning correction coefficient data in the same area.
The steps 23 to 25 correspond to the learning correction amount correcting means.

Kl _(oew) ←Kl+/M (M is a constant, M>1) Next, in step 26, the engine speed is calculated from the integrated value ΣN of the engine speed N, the integrated value ΣTp of the basic fuel injection amount Tp, and the sampling number m. The average value of N=ΣN/m and the average value of the basic fuel injection amount Tp=ΣTp/m are calculated. This part corresponds to the engine operating state averaging means.

Next, in step 27, Tp and center value of N of the area currently being studied are determined, and N and Tp obtained in step 26 are calculated.
and _{the average value of}
are corrected by minute amounts ΔN and ΔTp, respectively, and the data of the lattice axes of all regions are rewritten. Correcting the lattice axes of all regions by learning one region at a time in this way means that if you modify only the lattice axes surrounding the region currently being studied, the pitch between the lattice axes will be the same as the initial state. Therefore, all lattice axes are corrected in the same direction. This portion corresponds to the lattice axis correction means.

After this, in step 28, Δα ₂ is calculated for the next calculation.
Substitute the value of Δ into α ₁ , and in step 29, ΣN, ΣTp,
Clear each value of m.

If it is determined in step 11 that the engine operating state is no longer in the same range as the previous time, the count value C is cleared and the flag F is reset.

In this embodiment, the engine operating conditions are N and Tp.
In this embodiment, the area is divided by the upper, lower, left, and right lattice axes, but the present invention can of course be applied to the case where the area is divided by one parameter.

Specifically, in the idle speed learning control device,
Set the basic control amount ISCtw from the water temperature, search the learned correction amount ISCle from the water temperature, compare the target idle speed Ns set from the water temperature with the actual idle speed, set the feedback correction amount ISCfb, and set the feedback correction amount ISCfb using the following ( 1) Control amount to the idle control valve 10 by equation
ISCdy is calculated and learning is performed according to the following formula (2) in a steady state (for example, after a predetermined period of time has passed since the engine became idling). In this case, the learning correction amount is stored for each engine operating state. Although the regions are divided based on one parameter, water temperature, the present invention is also applicable to this case.

ISCdy=ISCtw+ISCle+ISCfb...(1) ISCle _(oew) ←ISCle+ΔISCfb/M...(2) The idle control valve 10 is equipped with a valve opening coil and a valve closing coil, and pulse signals in these coils are mutually determined. The opening degree is adjusted according to the duty ratio of the pulse signal, and the above-mentioned ISCdy is the time percentage (%) that the valve opening coil is ON.

<Effects of the Invention> As explained above, according to the present invention, when the learning correction amount is learned and stored for each region of the engine operating state, the grid axes that partition the region are automatically corrected by learning. This makes it easier to match the area settings, and also accommodates the driver's habits, resulting in optimal efficiency (ease of learning, accuracy), and improved learning speed.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing the configuration of the present invention.
FIG. 2 is a block diagram showing one embodiment of the present invention, FIG. 3 is a block circuit diagram of the control unit in FIG. 1, FIGS. 4 and 5 are flowcharts showing control contents, and FIG. FIG. 7, which is a schematic diagram of the learning correction amount map, is a time chart showing the relationship between the O ₂ sensor output and the feedback correction amount. 1... Engine, 6... Air flow meter, 10...
...Idle control valve, 11...Fuel injection valve, 16...
... _O2 sensor, 17...Crank angle sensor, 30
...control unit.

Claims (1)

[Scope of Claims] 1. Basic control amount setting means for setting basic control amounts corresponding to control target values such as air-fuel ratio and idle rotation speed, and a grid that divides the engine operating state into a plurality of regions according to the parameters thereof. rewritable storage means that stores the axes and learning correction amounts for correcting the basic control amount for each region surrounded by these grid axes; a learning correction amount search means for searching a learning correction amount for a region; and a feedback correction amount for comparing the control target value and the actual value and correcting the basic control amount so as to bring the actual value closer to the control target value. a feedback correction amount setting means that increases or decreases the amount, the basic control amount set by the basic control amount setting means, the learning correction amount searched by the learning correction amount search means, and the feedback correction amount setting means setting the feedback correction amount. a control amount calculation means for calculating a control amount from the feedback correction amount; a control means for operating according to the control amount to control an air-fuel ratio, an idle rotation speed, etc.; A steady state detection means detects a steady state by detecting a steady state by detecting a steady state; a learning correction amount correcting means for correcting and rewriting a learning correction amount corresponding to a region of the engine operating state; an engine operating state averaging means for calculating an average value of the actual engine operating state during learning of the deviation; an internal combustion engine comprising: lattice axis correction means for correcting and rewriting a lattice axis that divides a region in a direction in which the average value of the engine operating state becomes the center of the region including the average value of the engine operating state at the same time as correcting the learning correction amount; Learning control device.